Submarine



Jan. 15, 1924.A 1,481,230

F. ROVETTQ SUBMARINE Filed Dec. 13. 1922 G sheets-sheet n fyi-2 7 ,12 if "E j 2.9 35? j j; 16 den lll 2" 'i'. z @a 59 Ya 5 1 3 3 l l l' Jan. 15, 1924. 1,481,230

' F. RovETTO SUBMARINE Filed neo. 1s. 1922 s sheets-'sheet 2 Jan.v15, 1924.` 1,481,230

F. ROVETTO SUBMARINE Filed Dec. 13 1922 6 SheeliS-Sheei 5 Jan.. 15 1924."

F. ROVETTO SUBMARINE l Filed Dec. 15, 1922 6 Sheets-Sheet 4- 1,481,230 F.RovETTo SUBMARINE.

Filed nec. 1s. 1922 @Sheets-sheet 6 109 fm j! A6 122; n f .292 1211519 n d i? 116'Z141 g Patented Jani. 15, 1924.

FRANCESCO ROVETTO, OF SPEZIA, ITALY.

suenaninn.

Application filed December 13, 1922. Serial No'. 666,670.V

To all 'ur/'wm it may con cern lle it known that LFaANonsoo Rom'r'ro,

a subject ot the King of Italy, and residing at the ljoyal Arsenal, Spezia, italy, haveinvented certain new and useful Improve- -ents in Submarines, ot which the followw ing is a ecitication.

The object of the invention is an apparatus ror maintaining a submergible submaif rine automatically in equilibrium betweenV two waters while its driving motors are at rest. The apparatus attains thisscope by causing the submarine being submitted to' variations of weight in accordance with determinate laws. These variations of Vweight aro obtained automatically through successive admissions or' water into, and-discharges or water from the submarine. Asa consequence of the variations of weight the sube marine moves with an oscillatory motion while keeping itself on the same vertical line and moving up and downwards. The successive variations of weight tale place'in accordance with the following laws:

l. Buring the downward movement of the suljmariiie the variations ot weight are negative (discharge of water) so that the weight ot the submarine during the downward movement is continuously decreasing',

Q. During the upward movement of the submarine the variations of weight are positive (admission ot' water) so that the weightV ot the submarine during the upward moveinentis continuously increasing?V The successive variations ot weight during the upward movement between the limits of depth within .whichthe submarine is intended to remain, are of equal value and they taire place after the submarine has covered determinate intervals of space, so that the total variations of weight are a function of the spaces covered and in particular the;v are proportional to the spaces covered in case these intervals of space are equal hetween them,

l. rEhe successive variations of weight during the downward movement between the lini ot' depth within which the submarine is intended to remain, are ot equal value and tal-:e place aller the submarine has covered determinate intervals ot space, so that the total variations ot weight are a Jfunction ot the spaces Covered and in particular they are proportionagto the spaces covered in case these intervals of space are equal between them, Y

VIV-hen the submarine has reached the preestabiished maximum or minimum limits of depth, the variations of weight, instead or' talring place in proportion to the spaces covered, mayV take place in proportion to time, so

that the downward or upward movement of the submarine is rapidly stopped and the distances by which the submarine may go be` yond these limits are reduced to a'minimum.

6. ln a rst period of time the variations of weight during the successive downward movements. are ot greater value than those which take place during the upward inovements, so that the spaces covered by the submarine during the downward movement are `smaller than those covered during the upward movement and the submarine, thoiughy continuing to oscillate, has a tendency to rise until it reaches the minimum limit of depth, Y

7. After `the submarine has reached this minimumV limit of depth a second period begins in which the variations ot weight durf ing the successive downward movements are of smaller value than those which take place Vduring the upward movement7 so that-the submarine, although it continues to oscillate,

has a tendency to descend until it reaches the maximum limit of depth. After this a third period begins which is'similar to the firstpe- Yriod and wherein the variations of weight during bthe downward movements are of greater value than those which take place during the upward movements, so that the submarine has a tendency to rise, this third period being followed by a Jfourth period similar to the second period, and then by a tth period similar again-to the firstY period, and so on.

Figure 1V shows theniotionY ot the submarine as it is generated by variations otl weight in accordance with the above cited rules. The axis of the abscissas carries the periods ot time, the axis of the ordinates the spaces. rlhe line l-Q indicates the water level, the line S-d the minimum limit of depth hnthe line 5--6 the maximum limit of depth 71,2. Y

While oscillations caused through casual variations of weight or of thrust of thcsuhmarine on account ot the resistance of the water to its motion, are gradually decreasing in width until they take the amplitude of those' oscillations which are due to the va- Vriations of weight produced as described.

The working of the controlling device is c based on the variations of vpressure whichl take piace when the depth varies. The sec-f ond Vdevice generates the variations of weight by allowing successive admissions ot water into, and discharges of water out of the submarine. The Vconnection betweenY the i'irst and the second device is resilient.

The arrangement of the,y apparatus on 'board the submarine as hereafter .described is givenjby way of examplel only and. iii

practice it may be widely modified to adapt the apparatus iii the simplest way to submarines of any type and construction. Y

TheY apparatus will be described with reference 'tof the accompanying drawings, wherein- Figure 1 is a diagrammatic showing of the `motion of a submarine according to this invention.

Figure 2 is a Vhorizontal section along the top part of the rooms of the submarine wherein the apparatus is lodged,

Figure 3 is a. longitudinal section along line 3-v-3 :of Figure 2, Y Y

Figure 4 is a cross section on line 4-4 of Figure 2,. .y Y

, Figure 5 illustrates the construction of the inlet andvoutlet valves,

Figure 6 shows a valve arranged on the piping from the outlet valve to one of the iaissons, ,v A Y Figure 7 is an elevational view of a safety valve,V Y Y Figure 8 isa view of a valvearranged on die piping from the inlet valve to onek of the zaissons,- Y f .Y Y

Figure 9 shows a detail of this valve,

Figure l()v shows another detail,

Figure 11 illustrates the inlet valve for `he ,compressed air, .Y Y

Figure 12 is ja schematical view of the ontrolling device for-the valves,

Figure 13 is a sectional view of a metal ontact bar along line A-A of Figure 14,

Figure k14is an elevation of this bar,

Figure 15 is a sectional view of a contact nit along line B-B of Figure 16,

F igure. 16 is an elevation thereof,

Figure 15v4 and FigurelV are similar views of a Vmodi-V ed form of the contact unit, Y Y

Figure 17 is a sectional view along line `'--C of Figure 16, h

Figure 18 isa cross section of another intact unit, Y

Figure 19 is a horizontal section of the contact members and the cooperating l same parts,

' Figure 21 is a vertical section thereof at right angles to Figure 20, Y

Figure 22 shows a Vmodied form of the pipe 67,

Figure 23 is an elevation of one of the 'contact units, ,Figure 24 is a scheme of the electric con- Vnections.

ii/lith reference to Figures 2, 3 and 4, 11, l2 and 13 are three concentric cylindrical Vcaissons whose axis Vpasses through the YYcentre Yof gravity of the submarine.' The caisson 11 has lodged in it the various members of the apparatus, the tightlyrclosed caisson 12 serves to contain compressed air and the waterY which is discharged during the working lof the apparatus, the caisson 13 whichV is in communication with the inside of the submarine, Vreceives the water which enters the submarine during the working of the apparatus. Y

The device which generates the variations of weight comprises, as shown in Figures 2, 3, 4, two vordinary Kingston valves 14, 15 which communicate with the sea and are permanently open during the working of the apparatus. AnV outlet 'valve 16 communicates on the one hand by means ofY the pipe 17 with the Kingston valve 14 and on the other hand through the pipes 18,-

19 withA the caisson 12, a valve 2U bein interposed in this piping. The water wf ich is discharged from the caisson 12 into the sea flows through the pipe 19, the valve 20,

the lingston valve 14.

An inlet valve 21 communicates on the one hand through the pipe 22 with the Kingston valve 14 and on the other hand by means or' the pipes 23, 24 and Vthrough'l the valve 25 with the caisson 13. The Water which enters the caisson 13 from the sea, Hows through the Kingston valve 14, thev pipe 22, the valve 21, the pipe 23, the valve 25 and the pipe 24.

A pump 26 which is always in motion during the working of the apparatus, sucks up water from the caisson 13 through the pipe 2T and transports it through the pipe 28 into the caisson 12 so that the air contained therein is compressed. safety valve 29 serves to maintain unaltered the diiierence betweenthe pressure of the water in the caisson 12 and the outside pressure of the sea independently of the depth of the submarine. The valve 29 communicaes on the one hand through the pipe 30 with the caisson V12 and on the other hand through the pipe 31 with the caisson 13.

2i valve 32 permits compressed air from the compressed air containers of the sub- Y i. Y

the pipe 18, the valve 16,V the pipe land'V izo CII

marine being admitted into the caisson 12 through the pipes 33, 34 when on account of the speed of the downward motion of the submarine the water supplied by the pump 26 is not suficient to maintain the required pressure within the caisson 12.

The outlet valve 16 and the inlet valve 21 are of identical construction and they are each controlled by a solenoid. These valves are illustrated in detail in Figure 5 wherein 35 is the valve box which is provided with two nozzles. 36 is the cylinder which has two or more series of circumferential openings 37 and is secured by bolts to the valve box 35, a packing 38 being interposedv between the cylinder and the bottom of the valve box, to prevent leakage. From the cover of the valve cylinder is extending upward the pipe 39 which is screw-threaded at its upper end. Within the cylinder 36 is slidably arranged a piston 40 provided on its cylindrical part with circumferential openings which are 'identical with those of the cylinder. A soft iron piece 41 is connected with the piston, while a second iron piece 42 isscrewed onto the upper end of the pipe 39. The pipe 39 and the soft iron piece 42 are surrounded by a solenoid 43.

Vihen electric current is passing through the solenoid 43, the piston 40 is carried upward by the soft iron piece 41 so that its apertures are brought opposite the apertures of the cylinder 36; in this way the valve is made to open. When the passage of current is interrupted the piston falls downward and the valve closes.

The valve 20 which is shown in detail in Figure 6 is controlled by means of a solenoid and serves to adapt t e apparatus to the requirements which are s'et out under rules 6 and 7. During the periods when the submarine must have the tendency to rise the valve 20 remains permanently and completely open, while it remains permanently, but

v partly open when the submarine must tend to descend. This valve 2O is constructed like the valves 16 and 21. When no current passes through the solenoid the piston 44 is in its lowermost position and only a part of the area of its apertures is opposite the apertures in the cylinder 45. When current passes through the solenoid the piston is caused to rise and its apertures are with thelr whole area opposite those of the cylinder.

The safety valve 2 9 shown in detail 1n Figure 7 has the purpose to prevent variations of the diiference between the pressure of the water in the caisson 12 and the outside pressure of the sea, independently of the depth o f immersion of the submarine. 46 1s the valve cylinder which is closed both at the top and at the bottom by a cover and carries two nozzles 47 48. In correspondence with each nozzle there are provided circumferential apertures on the cylinder. 49 is the piston. which carries two series of circumferential `apertures 50, 51 which intercommunicate by means of the channel 52 arranged along the axis of the piston. The lower part of the cylinder communicates through the pipe 53 with the caisson 12, while the upper part communicates through the pipe 54 with the sea through the Kingston valve 15.

The nozzle 48 communicates with the caisson 12 .through the pipe 30, while the nozzle 47 communicates with the caisson 13 through the pipe 31. When the pressure of the water in the caisson l2 against the bottom of the piston 49 is larger than the sum of the weight of the piston and the pressure of the water of the sea against the top; of the piston the latter is made to rise so as to bring its two series of apertures 50, 51 opposite the apertures provided in the cylinder, whereby the caissons 12 and 13 are put in communication through the nozzles 48, 47. Vater then passes from the caisson 12 to the caisson 13 and the pressure in the caisson 12 diminishes until the piston 49 redescends. In this way the valve attains the scope for which it is intended. The constant diii'erence of pressure per unit of surface of the water in the caisson 12 and that of the sea water is evidently equal to the weight of the piston 49 divided by the area of its 'cross' section.

The valve 25 shown in detail in Figures 8, 9 and 10 serves to control the useful width of the apertures through which water from the sea enters the caisson 13 so that the volume of water which iows through these apertures in a unit 'of time remains constant no-matter which is the depth of immersion of the submarine.,

55 is the valve cylinder which is closed both at the top and at the bottom by.a cover and carries two nozzles 56, 57. Opposite each nozzle there is provided in the cylinder an aperture 58 having the particular shape shown schematically in Figure 9. The nozzle 56 communicates by meansof the pipe23 with the valve 21, while the nozzle 57 communicates through the pipe 24 with the caisson 13. The top part of the cylinder communicates by means of the pipe 59 with the sea through the Kingston valve 15. 60 is the piston of this valve, which said piston has a cross opening 61 (Figure 10) and is supported by the spring 62.

When the depth of immersion of the submarine increases the pressure against the top of the piston grows and the piston descends so as to compress the spring 62. The opening 61 of the piston which was opposite the two oppositely arranged openings 58 in the cylinder, will be brought, when the pressure increases, to move away from these openings so that same will be more and more throttled as the depth of immersion ,aug-- lll ments.-` The two 'apertures 58 are vcalculated so that the 'volume of water which l'l'owsv throught same independently of the'depth of the submarine." A

The? valve 32 which is illustrated in de-v tail in Figure 11 serves to permit the flow of compressed air from the compressed air containers of the submarine into the caisson. 12 whenthe water supplied by the pump 26 is not sufficient to maintain' the required pressurevin thecaisson on'account ofthe speed-with"- which the submarine is moving downward;

63 is the cylinder ot this valve which is closed both' at the top and at the bottom by a cover.` It communicates at the to) by means of a pipe 6d and through the l ings? ton valve -15 with the sea andat the bottom through thel pipe with the caisson 12 and through-the piped?, with-the compressedY air containers of the submarine.- Inside the cylinder'is arranged a vertically slidable piston 65. When the pressure against the bottom :tace of the piston, which is equal to the pressure prevailing in the caisson 12,

is greater thanthe pressure ot the water vof the sea against the top ot' the piston increased by the weight of this said piston, lthe latter risesand closes the valve 66^which is carried"`alongby a rod connected `with the piston. When onthe other hand the pres-v sure in the .caisson A12 lis belowv therequired pressurey as` the water supplied'by the pump is' not suiicient on account ofthe speed'ot the downward'mo'vement o1" the submarine, the piston '65V moves downward andopens the valve 66 so that compressed air Hows from the containers on the submarine into thevcaisson 12.

, The weight of the piston 65 is such that the valve-66 opens when the diierence be-V tweenthe'pressurefin the caisson 12and that of the sea is below a certain minimum value.

The device which causes the valve-s 16,20,

21 to operate at the required momentand which-permits the passage of'electric cur` rent through these valves is shown schematically in Figure 12. This device consists of a pipe 67 which communicates at the bottom .with a container 68 which in turn communicates withfthe sea through the `pipe 69 and the Kingston valve 15 Above the pipe 67 is arranged a second pipe 70 which .communicates with a container 71. 1vVith the. exception of -the opening towards the seav the wholelfa'rrangement of the pipes 67, 70 and of thelcontainers 68, 71 .is tightly closed.

When? thek submarine is submerged and the Kingston valve 15 is open, water-from the sea enters the container "68 and a part.

of the pipe67 so as to compress the aircontained inl the controlling4 device. The volumes of the containers 68,71 and ,of the pipes 67, -70 are such that the container 68 is'full the valve 25 remains always theof water when Vthe submarine is completely underwater with the exception of the top of the perisc'ope, while the water level in the pipe 67 is'at the li'ne 72 when the submarine is at the minimum limit of the depth of equilibrium, and the water level is at, the line 7 3 when thevsubinarine is at, the maximum limit of depth of equilibrium. When the water level in the pipe rises or descends a float '711 will riseV or descend and will draw along with it by aid ot a rod an electric switch 7 5 which moves within the pipe 70 and is adapted to engage contacts within moment a passage of electric current through the solenoids which control the valves 16, 20, 21. The lines 7 2, 73 of the water level in the pipep67 correspond with two positions 721, 73I ofthe switcli'75 in the pipe 70.

The electric contacts are shown in Figures 13-23 wherein the parte made et ebonite are shown by cross lines. These electric contacts are arranged inside the pipe 70 along the generatrices displaced by 9()o one from the other (Fig. 19).

Along one generatrix are arranged the two series of contacts 7 6, 77 which are insulated one from the other by means of an ehonite bar 78 and from Athe pipe 70 by means of an eb'onite bar 79. Both the series otcontacts 76 and the series of contacts 77 are formed of armetal bar having the same length as the pipe 7 0l and carrying projections 80. Figures 13 and 14 show respectively the profile and the elevation of these parts, Figurel being a sectional view along the line A-Aot Figure 1%. The two series of contacts 7 6, 77 and the ebonite bars 78 are combined in the manner shown inare insulated one from the other by an ebonite bar 88 and are identical with the Contact series v7 6, 77 and the ebonite bar 78.

In case it is desired that beyond the limits of depth of equilibrium the variations of weight-'ofthe submarine should be proportional to theperiods ot time instead ot being a functionofthe spaces, the bars 76. 77, 8i

les

and 82 above the line 73I and below the line 72I (Figure 12) may have the shape and be combined as shownv in section and in Velevation in Figures 15 and 16. In this case theprojections 8O arevabolished and thetwo bars present an uninterrupted surface -towards the. inside of the tube 70.

If it' is `desired that the variations of weight within the limits ot depth of equilibrium be proportional to the spa-ces covered it is necessary: that the interval between the successive contactso the series 76, 77, 81,

82 should not have a constant value,'but they must have a decreasing width on their approach towardsthe top. The same purposemay be obtained and the width of Vthe interval between the Ycontacts may remain unaltered when using a pipe 67 which is not cylindrical as shown in Figure 12, but has cross sections of Vdecreasing area. towards the -top witha profile as shown in Figure V22. The formula which gives the values of the area of these sections as a function of their position in the pipe may easily be found through calculations.

Along a generatrix which is displaced by 90 respecting the above described contacts there is arranged a contact 84 which consists of a metal bar having the cross section shown in Figure 18 and having the same lengthY as 'the pipe 70 from whichit is insulated. j Y

Opposite the contact 84 there is provided a metal bar 85 which has also the cross section shown in Figure 18 and has the same lengthas the pipe 70 from which it is insulated, The bar 85 is interrupted at two points to lodge the contacts 86, 87 which are insulated therefrom Fig. 23).

The switch is shown in Figures 19, 20 and 21 and it comprises four rollers 88, 89, 90 and 91. The rollers 88 and 89 are interconnected bythe plate spring 92, the rollers 90, 91V by the plate spring 93. The two springs Y Vare held together by an ebonite piece 94.

` springs 92, 93 (Figure 20).

The spring 92 has secured to it the electric contact 95 which rests on the top face of the ebonite piece 94, while the spring 93 carries an electric contact 96 which bears against the lower face of the ebonite piece 94. The two rollers 88, 90 are made of metal, the two rollers 89, 91 of ebonite. The four rollers are guided by the contacts 80 of the series of contacts 7 6, 77 and 81, 82.

The combination of the rollers, the springs and the ebonite piece 94 is prevented from descending through it beingv held in an in` dilferent equilibrium by a counterweight securedto the wire 128 connected with the The switch comprises further four rollers 97, 98, 99 and 100 which are connected in pairs by the plate springs'101 and 102 secured to a metal ring 103 which is connected by means of the ebonite piece 104 with the rod of the float 74. The four rollers are guided by the bar 85 and by the contact member 84. The two rollers 97, 99 are made of metal, while the rollers 98, 100 are of ebonite.

The working of the device is as follows: When the submarine is gradually submerging and the ioat 74 in the pipe 6T moves upwards, the ring 108 will engage with its bottom face the contact- 96 and carry it upwards together with the ebonite piece 94 and with the springs andthe rollers c connected thereto. During this upward movement of the switch the contacts 80 of the series 81, 82 are alternately engaged by the roller 90 and the Contact member 84 is thus alternately connected with the contact series 81, 82. Y Y l 1When on the other hand the submarine rises and the float 74 descends, the ring 103 will engage with its top face the contact 95 and the contacts 80 of the series 76, 77 will be alternately engaged by the roller 88, so that during this movement the Contact member 84 will be alternately connected with the Contact series 76, 7

When the water level in the pipe 67 isV at the line 72 (Figure 12) and the submarine therefore has reached the minimum limit of depth of equilibrium the roller V97 engages the contact 87 and in this Vway connection is setup between this contact and the contactj84. Y Y

When the water level in the pipe 67 is at the line 7 3 and the submarine therefore has reached the maximum limit of depth of equilibrium the roller 97 engages the contact 86 and connection is thus set up between this contact and the contact 84.Y

As it is not convenient to have the switch traversed by the current of rather high intensity which ,passes through the solenoids of the valves 16, 20, 21, tive auxiliary electromagnets are made use of which also serve the purpose of holding the valves 16, 21 open for a constant period of time for each aperture.

A scheme of the electric connections for the controlling device is shown in F igureV 24 wherein the series of contacts 76, 77 81 and 82, the contacts 84 and the bar 85 are shown laid out in one single plane.

In this figure 105 is the current generator and 106, 107, 108 are the solenoids which control respectively the inlet valve 21, the outlet valve 16 and the valve 20. 109 is the auxiliary electromagnet of the solenoid 106 and thus of the valve 21. 110 is the auxiliary electromagnet of the solenoid 107 and therefore of the valve 16. The auxiliary electromagnet 111 which in the figure appears twice, serves for the control of the solenoids 106, 107 and thus of the valves 2l and 16 in the manner hereafter described. 112, 113 are the auxiliary electromagnets of the solenoid 108 and thus of the valve 20.

When current is passing through the electromagnet 109 the latter attracts its armature 114 so as to cause the lever 115 to rotate about its fulcrum 116, whereby the funnel-shaped member 117 is immersed Vinto the mercury contained in the glass 118. When the passage of current through the electromagnet 109 is interrupted the armature 114 falls back and I the mercury, while the passage of current lnegative pol Ythe lei-er120'to rotate ahoutits fulcrum121',

thev endrof this lever engaging *theY contact 122 so as vtoconnect the electromagnet 100V With the positive pole of the 'current genh erator.v When current is passing` through the electromagnet 109 vand its armature isn about tov engage the poles, the end ot' thllever 115 strikes against the end ofithelever 120'so as to,A disengage it kfrom the` contact 122. In this Way; the passageV of current through the eleetromagnet 102 is "intere rupted,` the funnel 117 VArisesa'nd current continues to pass,` as above said, through the solenoid 106 for va detern'iinate period of time until all the mercur7 has leftthe't'unnel.r In this' Way, `the successive apertures of the valve 21A controlledby the 'solenoid 106 are eausedto have equal duration.Y

The same events takepla'ee for'the'electroinagnet 110 Which'controls thesolenoit 107 and therefore the 'Valve 16.

YVhen current is passing through the electromagnet 112,`the Ylever 123 is caused to rotate about its fulerum 12% andV its down-V ward bent end enters the mercurg7 contained in the glass 125 so as topermitthe passage of current through the solenoid 10S which causes the piston of the valve 20 to Vrise,` this Valve being thus caused to open completely. -As' the lever 123 is'inan indi'erent equilibrium its end continues to be imniersed'in theanercurya'nd therefore cur#l rent Vcontinues to pass into the solenoid 108 also when the current is nolonge'r passing through the electromagnet 112. W'hen current is passing through the electromagnet 113, the `lever* 123 rotates in the opposite direction? its end is no longer immersed Vin the mercury, the passage of current through the solenoid 108 is interrupted and the. piston of the Valve 20 Jfalls back so that Ythis Valve remains onl7 partlyT open.

In Figure 2st the fulllines show the circuit ofthe auxilary*electromagnets and the dotted lines the circuits of the solenoids 106, 107 and 108.Y

The circuits of the auxiliary electromagnets Work as follows.-

As regards the electromagnet 111 it is evident from Fig/furet 24-that wherirthe switch during its upward* movementl engages through its roller 90;Y the contacts'vof theseries 82 or during'fitsrdotvnwardfmoveineht through'its roller 88 thejcontacts'o the series77, electric current passes through electromagnetlll, fthe series 82 orthe series 77,#theswitch andthe (contact .ASQ/toithe l Y *l* electric electro-.V

As regards the electromagnet 1097 the cur, rent passes throughthe lever 120 Vcontrolled by the electromagnet 111,` through the'con tact 122 and the electromagnet 109 Aand flows to the Contact series 76. Y submarine rises and Vthe switchV therefore When tue descends, the contact series 7 6 is put in coir.-V

munication with the contact Slteach time the roller 88 of the switch engages onegof the contacts of the series76. The current passes then through the electromagnet A'109;` V.But as soonas theend of thelever 115 goes downward and removes thefend'ot' the lever 120 from thef`contact7122, the passage of current through4 the elect-r'ornafjrnetVV 109Iis interrupted. dcmrnwardV movement it engages withY its roller' 88 the successive magnet 109. Y

' ln this'w'ay the purpose is attainedrthat theA value 21 is `caused to kopen after the'sul1 marine has covered determinate rintervallsgof space, and that Vit is held ropen for afoonstant period of time at each aperture. TheL action ciE the Valve.'l 25 Whi'chthrottles the inlet openingsin accordance `with the Vdepth `Y As the switch 'continues'-V itsf of immersion of the submarine While securf ing for any depth the 'fio'wioi constant volume or' Water through this Va-lve, and the fact that the Y the'valve21 is constant, hare-the result that the-quantit'nxjof Water which enters the subY marine 'at eaclr'aperture of this ifalie isconstant. 'f

The' description regarding the elect-ro duration 'otea'ehf aperture of.

magnet 109 applies also tothe electromagnet 110 -Which controls Athe solenoid l1.07 and therefore the outlet valve 1G, It Awill thus be edent that at'eachapertur'e of the'valvc 16 thc'quantity of' vWater that is discharged from the Vsubmarine is constant and equal to a maximum Value for'all the'aperturesthat l take place during the periods when thesub4 marine 4tends tofrise, and it is constantand.V`

equal to a minimum Value for all thefaper-VV the periods 'wherein the'suhmarme has the tendency'to Y tures which take Vplace during descend.

In fact, for any vc lepth Vof immersion of 'the submarine the difference of pressure between .Y

the' inside of the caisson 12 yand the outside;

is'ronstant and'forthisreason the speed of the liowof the Water through the va'lvel`20 remainsY constant g further, the duration of.' the aperture of'the'yalve 16 is'constant for alll the apertures on 4account ofV` the use of*V the the mercury;

As regards the electrornagnets 113, 112,1the

' tunnel-shaped conta'ct'me'mherd which VAenters n IgienaexoV magnet 113 only whentheroller 9T of the Vdischarging on switch engages the contact 87 and puts in communication this contact, and therefore theV electromagnet 113, with the contact 84 Vand thus with the negative pole. The current passes insteadV through the electromagnet 112 only when :the roller 9'? of the switch engages the Contact 86. The two electromagnets control by aid of the solenoid 10S the valve 20 in the manner above set out..

ln the place othe electromagnets 109, 110, 111, 112 and 113 small solenoids might be used within the scope oi the invention.

The circuits of the solenoids 105, 107 and 108 are shown in the Figure 24 and it is thought that no Jfurther explanation is required.

ln case beyond the limits of depth of equilibrium the variations of weight must be proportional to the periods of time and not to the spaces and the series of contacts 76, T7. Sl, 82 below line 72 and above line 7?? (Figure 12) are therefore constructed as shown in Figures 15 and 16', the passage of current through the solenoid 106 when the submarine is rising, and through the solenoid 107 when the submarine is descending, taires place without interruptions and the valves controlled thereby remain always open.

The limits ot the depth of equilibrium h1. it., may be altered at will in the Jfollowing way. `When introducing into Ythe pipe (Figure 12) through the valve 126 com: pressed air talren Jfrom the compressed air rontainers of the submarine, and when thus causing the quantity of air contained in the controlling` device being increased, the limits of depth k1, h2 will be augmented. When the other hand through the valve 127 a part of the air contained in the controlling device, the lim'ts of depth will be diminished.

.another way ot Vvarying the limits of depth of equilibrium might be that ot employing besides the contacts 86, 87 (Figure 2li) along the guide 85 other contacts 861, STI which may be inserted at will in the circuit ot the electromagnets 112, 113 while the contacts 86, 87 are cut out.

lt is evident that the constructional details ct the apparatus as above described may be varied within the scope of the invention and within the limits ot the claims hereunto annexed.

What I claim is:

1. A method for maintaining a submarine in equilibrium between two water levels, while the driving motors are stopped, comprising causing admissions ot water into the submarine as soon as the latter commences to rise and continuing during the entire space covered during upward motion, and causing discharges ot water from the ,submarine as soon as itcomniences to descend and continuing durmg the entire space covered during downward motion, the quantity of the water Ythat ent-ers and the quantity of 'water that leaves the submarine, being, in their totality1 a tunction'oi" the spaces covered during upward and downward motions.

2. An apparatus for maintaining a submarine in equilibrium between two water levels, while the driving motors are stopped, comprising, a controlling device, including a pipe which communicates with the sea, a iioattherein which is caused to move, di-V rectly through the action of the water of the sea said i'ioat carrying an electric switch. admission and outlet valves, solenoids Jfor controlling the valves, said switch permitting electric current to pass at intervals through said solenoids for opening said valves in proportion to the space covered by the float and thus by the submarine.

3. An apparatus according to claim 2, there being a plurality7 ot contacts provided in the said pipe ot the controlling device, said contacts controlling a magnetic valve arranged on outlet pipingwhereby to increase the opening of such valve when the ubmarine tends to reach the upper limit oi" the depth of equilibrium, and to reduce such opening when the submarine tends to reach the lower limit or the depth ci equilibrium.

4. An apparatus according to claim 2, comprising, in combination, a water pump. a caisson, and a return valve for maintaining a pressure in the caisson which exceeds by a constant value, the outer pressure, irrespective ot the depth of immersion ot the submarine.

5. An apparatus according to claim 3, comprising in combination, a water pump, a caisson, and a return valve tor maintaining a pressure in the caisson which exceeds by a constant value, the outer pressure, irrespective oi' the depth ot immersion ot the submarine.

6. An apparatus according to claim 2, comprising, in combination, means Jfor controlling admission ot air into and discharge of air from, the pipe or" the cont-rolling device, whereby to vary the limits of the depth ot equilibrium.

7. An apparatus according to claim 3, comprising, in combination, means tor controlling admission ot air into and discharge of air from, the pipe of the controlling device, whereby to vary the limits ot the depth of equilibrium.

8. An apparatus according to claim 4. comprising', in combination, meansV Jfor controlling admission of airY into and discharge of air trom, the pipe ot the controlling device, whereby to vary the limits of the depth et equilibrium. Y

9. ein apparatus according to claim 5,

' Vice, whereby `t0 vary the limits'f the VV(eptli FRANCESCO ROVETTO' Y 5 of equilibrium. Y Vitneysses;V

In testimony ywhereof I have"` signed at'. Y RICARDO DEIGADO, 'Gen0a,' Italy,` thisA 27th' day f lovmbeY GIOVANNI SEROLO. 

